When computers are employed for the layout editing of electronic documents, object snap functions are frequently used by electronic document layout editing tools to position objects at desired locations. When, for example, an object is continuously selected by means of a mouse and is moved (dragged) to a desired grid, the snap function aids in the object's being automatically arranged on a grid in a work area or on another object.
An electronic document layout editing screen is shown in FIG. 8. A plurality of vertical grids 101a to 101e and horizontal grids 102a to 102c are arranged on a screen 103. In the state shown in FIG. 8, a snap function has been used to move a selected object 100 to a position indicated by an object 100′. It can be seen that the object 100′ has been snapped to the vertical grid 101b and the horizontal grid 102b. 
This snap function is an important function for the efficient arrangement of objects relative to grids and other objects, and is very frequently employed by users. When the interval between grids used as references is short, or when many other objects are present, the snap function must perform more work than necessary to move a specific object to a desired location, and therefore moving the object smoothly may be difficult.
This problem will be explained while referring to FIG. 9. FIG. 9 is a diagram, showing a screen 103, for explaining the operating frequency of a conventional snap function whereby an object 100 has been moved to a location indicated by an object 100′. Assume that reference numeral 104 denotes a mouse (a mouse pointer), and 100a, 100b, 100c and 100d respectively denote the right, left, upper and lower sides of the object 100. A total of eight snaps (Snap 1 to Snap 8) occurred before the object 100 was moved to the location indicated by the object 100′, i.e., until the right side 100a snapped a vertical grid 101f. In this example, the left side 100b snapped a vertical grid 101b, the lower side 100d snapped a horizontal grid 102c, the right side 100a snapped a vertical grid 101d, the upper side 100c snapped a horizontal grid 102b, the left side 100b snapped a vertical grid 101c, the right side 100a snapped a vertical grid 101e, the left side 100b snapped a vertical grid 101d, and thereafter, the right side 100a snapped the vertical grid 101f. 
As described above, when the conventional snap function is employed, the function must perform more work than necessary to move a specific object to a desired location, and this hinders the smooth movement of the object.
A technique for improving the above described conventional snap function is disclosed in Japanese Patent Laid-Open Publication No. 2001-281835. According to the technique disclosed in this reference, of four snap points for an object selected by a mouse, only the snap point closest to the mouse cursor is set to a snappable condition, and is snapped as a snap candidate point.
According to the technology disclosed in Japanese Patent Laid-Open Publication No. 2001-281835, while it is possible to suppress unnecessary snaps caused when moving an object to some extent, only a snap point closest to a mouse cursor is in a snappable condition out of four snap points of the object and therefore there is a limit in the number of snap points in the snappable condition, thereby deteriorating the operationality problematically.
Moreover, in the conventional snap function, there has also been known a technology of inhibiting the snap function from being operated unnecessarily by temporarily invalidating the snap function with a combination of a drag-and-drop operation with a mouse and a keyboard operation, in other words, with a depression of a shift key or the like on a keyboard at the time of the drag-and-drop operation.
By using these conventional snap functions, it is possible to move the object relatively smoothly. These functions, however, require simultaneous processing of a plurality of operations such as the combination of the drag-and-drop operation and the keyboard operation, which necessarily requires operations with both hands and thereby deteriorates the operationality. Furthermore, it has been hard for a user to find the operation method of the combined plurality of operations and to learn the operation method.
Due to these circumstances, the foregoing conventional snap functions cannot move the object smoothly without deteriorating the operationality, thereby hindering an improvement in usability in object editing of an electronic document.